Astronomy at Phillips Exeter Academy

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It is that time of year again when we get to enjoy one of the best meteor showers, the Leonids. This one peaks mid-November and stems from the remains of Comet Tempel-Tuttle which has left its debris in a massive orbital path through which our planet passes yearly. This November the peak is on the mornings of November 17th and November 18th. This is not likely to be a storm shower, as we have enjoyed in the past. This is more likely to produce anywhere between 10 to 15 meteors per hour. As with all meteor showers, you will see more if you are far away from city and town lights and have clear, transparent skies. Here in the state of New Hampshire, it will also be chilly, so you’ll want a coat, sleeping bag, and some warm food/drink to enjoy while looking up. The meteors will appear to stream out of the head of Leo, the Lion. This is the sky for those mornings (click to enlarge):

Don Machholz, Shigehisa Fujikawa and Masayuki Iwamoto have confirmed a new comet which might very well become bright enough to see without optical aid. Stand by for updates here in the coming days as the orbital elements and ephemeris are corrected. The comet has been designated:

It appears that we might just have a bright comet for the end of 2018 and into the start of 2019: Comet 46P/Wirtanen. With a short period of just about 5.4 years, this time around the Sun, it will be very close to Earth (a mere 0.07AU or 11.6 million km) and enjoying its perihelion, too….. Predictions at this stage suggest a magnitude 3 object, well within the visibility range of the human eyeball. When and where to look? Here is an overall map of the comet’s path through December. Note that the perihelion date in December 16th, then the comet should be near its brightest:

Comet 46P/Wirtanen throughout December 2018. (click to enlarge)

On the night of 16 December for mid-latitude northern observers, looking south, this is what you should see…a lovely view of Orion and surrounding constellations. The comet should be near the Pleiades, making for a fine photographic opportunity.

A good meteor shower to watch is the annual Orionids. This one originates from the famous comet: 1P/Halley – yep, that one! As the comet orbits the Sun, little particles are left behind all over the place along the path. When our planet orbits through this debris, we see a meteor shower. This year, the peak night will be October 21-22, 2018… some time around 2:00am will be when the shower radiant is high in the sky. All you need is a good dark sky to view from. No optical gear is needed. Suggestions for those nearing winter: A sleeping bag, hot drinks, and some snacks. The image below shows that evening at about 1:30am local time with Orion rising in the southeast. The small red circle is the radiant from which the Orionid meteors will seem to emanate.

The sky as it will appear in the early hours of the morning looking southeast. The Orionid radiant: red circle.

Each August, the Earth passes through a stream of comet debris from Comet 109P/Swift-Tuttle. The comet will not be back our way until 2126… so… I wouldn’t wait up for that one. Along the orbital path, the comet has left behind small bits and pieces, most no bigger than a grain of sand. These run into our planet’s atmosphere and burn up due to friction. The result of this friction-filled reentry is a meteor, a rapid streak of light through the sky. This shower usually gives us about 60 meteors per hour at peak, and many fireballs: bright meteors that can even be bright enough to cast a shadow. How to see it?

Pick a clear night closest to the peak, which is on August 12th/13th.

Go to a dark sky site: avoid lights and cities. The darker, the better.

Bring something comfortable to lie down on: sleeping bags are good.

Bring food, drink, and bug spray if needed for your location.

Spend the night time hours looking up at the sky! No optics required other than your eyeballs.

Avoid lights! No cell phones. No flashlights. Your eyes take between 30-60 minutes to become dark adapted, and you lose that dark adaptation instantly if you see a light. Avoid lights!

The shower appears to come from a spot in the sky in the constellation Perseus. This rises just before midnight, so best observing will be after that, into the morning hours.

Mark your calendars for June 16th 2018: the Moon and Venus will slowly get to within 2.3 degrees of each other making for a lovely sight. All you have to do is head out in the early evening just after sunset and look to the lower western horizon. You might also catch some bright later-Winter stars as well. Here’s the view (click to make larger):

Venus and the Moon June 16th 2018 looking west after sunset.

While you are enjoying the view, take a close look at the Moon. You might just see something special, some Earth-Shine. When the unilluminated portion of the Moon is visible, this is due to sunlight reflected off the Earth, bouncing back to light up the Moon, and making it appear a faint eerie blue color. Binoculars will make this really prominent. Enjoy!

Now mid-March 2018 and there are planets in the sky! Here are some of the notable moments.

If you look to the west right after sunset you will catch bright Venus and fleeting (and fainter) Mercury. On March 18th, just after sunset, you might also be able to catch the very young, sliver moon, low on the western horizon.

March 18th 2018 looking west right after sunset.

Are you and early riser? Then you will be able to catch the other bright planets, Mars, Jupiter and Saturn.

Jupiter, Mars, Saturn and the Moon visible at about 5:30am looking southeast on March 12th 2018.

With some more time back at the regular computer, I have had the ability to merge some of the eclipse images together to make a solid HDR image of totality. This is what I call quite the Photoshop workout. This is a merge of 12 images ranging from innermost corona out to the outermost corona that did not wipe out the moon’s dark disk. Some 20 hours went into this. The star to the lower left is Regulus in Leo.

The eclipse was a perfect success! Clear skies prevailed throughout totality, with forest fire smoke and clouds coming in after it was all done. The temperature dropped from 88 to 68F, stunning! The corona was larger than those I had seen before. We had prominences and more. MANY images to deal with and not fast internet, so please be patient while I get these things edited and out there. It might take a while… a week or more. In the meantime, here are a couple of unedited shots.

Casper was most generous: we had an excellent space from which to observe: green grassy fields on to the hill to the east of town. The parking lot lights and grass watering sprinkler systems had been disabled for the day. The medical center even provided a lunch at the end!

Totality: This is the mid-corona using a longer exposure to show the fainter regions.

Totality: The inner corona. Note the fain, pink solar prominences on the right limb.

Partial stage as the eclipse begins. There are a few sunspot groups to see there.

The town of Casper, WY is now hopping along. A lot more people are here today. We started out with a visit to the Geology Museum on the southwest side of things. They have an excellent display on geologic time along with representative minerals and fossils from each period/era. They also have their very own T.rex skeleton, a nice surprise. It is being slowly picked out of the encasing rock….

So, there was a lot of good paleontology to enjoy there for sure!

Back into town, the place is swinging. Lots of people wandering about with geeky T-shirts… yes, these are eclipse watchers for sure. The town has closed off the central area for shops to show off their goods, for people to mill about, to have a quick bight to eat/drink, and relax in the summer sun, a hot summer sun, pushing to 90F. The skies today: crystal clear. Absolutely lovely.